CN100351890C - Signal processing method - Google Patents

Abstract

The present invention relates to a signal processing method which is used for processing the brightness gray-scale response speed of a screen panel. By means of a measurement mode, an over driving voltage measurement value (OD measurement value for short) needed by the brightness gray scales of different colors are obtained, and an OD measurement value table is made. Then, by means of a compression mode, corresponding four OD compression value tables are obtained by the OD measurement value table. When the present invention is used, an OD restoring value is obtained in a function operation way. The procedures are utilized for processing a brightness gray-scale response speed. The present invention is suitable for color display devices, such as LCD panels, plasma televisions (PDP), thin film transistor (TFT) displays or OLED, PLED organic electric excitation lighting display devices, etc.

Description

Signal processing method

Technical field

The invention relates to a kind of signal processing method, refer to a kind of signal processing method of saving great amount of hardware resources, can effectively accelerating intensity gray scale response speed and accurate performance actual color intensity gray scale especially.

Technical background

The quality of LCD performance has a kind of one response time of index, usually to the LCD following minute two states of making alive not: normal bright morphotype formula (Normally white, NW) and often deceive morphotype formula (Normallyblack, NB), wherein normal bright morphotype formula is meant that display pannel does not apply the picture that voltage is printing opacity, just bright picture, and often black morphotype formula is meant when display pannel does not apply voltage, present light tight state, just Hei picture; With normal bright morphotype formula is example, can be divided into two parts the response time:

(1) rise the response time: promptly applying under the voltage, the liquid crystal cell brightness of LCD changes to the 10% o'clock required time of reversing of liquid crystal, abbreviation " T from 90% _r"; And

(2) descend the response time, promptly do not applying under the voltage, liquid crystal cell brightness changes to 90% o'clock liquid crystal required turnaround time from 10%, is called for short " T _f".

Usually when the picture display speed surpasses 25 frames of per second (frame), human eye can be considered as continuous pictures with the picture of Fast transforms, but present home entertaining, for example play high-quality DVD film, the picture of fast moving when playing games, display speed is everlasting 60 of per seconds more than the frame, in other words, each frame period (frame interval) time is 1/60=16.67ms, if the response time of LCD is greater than this frame period time, the vestige that just occurs ghost or jumping lattice in the time of will causing display frame, have a strong impact on the quality of watching image, how promoting response speed must be from influencing the factor of response time, and following equation is respectively the response time T that rises _rWith the response time T that descends _fCalculation equation:

$T_r=\frac{r_1{\mathrm{<figure-callout\; id="2"\; label="d"\; filenames="C20041003744600121.png,C20041003744600132.png"\; state="\{\{state\}\}">d</figure-callout>}}^2}{\mathrm{\&Delta;\&epsiv;}(V^2-{V_{\mathrm{th}}}^2)}$ $T_f=\frac{r_1{\mathrm{<figure-callout\; id="2"\; label="d"\; filenames="C20041003744600121.png,C20041003744600132.png"\; state="\{\{state\}\}">d</figure-callout>}}^2}{{{\mathrm{\&Delta;\&epsiv;<figure-callout\; id="2"\; label="V\; th"\; filenames="C20041003744600121.png,C20041003744600132.png"\; state="\{\{state\}\}">V</figure-callout>}}_{\mathrm{th}}}^2}$

R wherein ₁: the coefficient of viscosity of liquid crystal material;

D: cel-gap;

V: the driving voltage of liquid crystal cell;

Δ ε: the dielectric coefficient of liquid crystal material.

There are four methods can reduce the LCD response time as can be known by following formula: to reduce coefficient of viscosity, reduce cel-gap, improve driving voltage and improve dielectric coefficient, the technology that wherein improves driving voltage is referred to as " quickening to drive " (over drive) technology, can transmit the voltage of increase to liquid crystal panel by liquid crystal driving integrated circuit (driverIC), the voltage that reverses of liquid crystal is strengthened, thereby liquid crystal is reversed quickly and reply to reach the brightness that image data is desired to present fast.

For R, G, B chroma-luminance GTG at existing 8 bits, 0 to 255 rank, implement above-mentioned acceleration Driving technique, each dealer must provide suitable acceleration driving voltage value.Yet 0-255 rank R, the G that changes between different time points, B chroma-luminance GTG respectively have the acceleration driving voltage value of its different demands.Only change in the brightness of the 0-255 rank of two different time points, will produce 65535 kinds of different acceleration driving voltage values with a kind of color signal.

If a LCD Panel will provide the suitable acceleration driving voltage value of R, G, B color signal of 8 bits, then it must store 65536 kinds of different acceleration driving voltage values at least, does not say naturally and can explain for the demand of storer, has more improved whole cost.Therefore, each tame dealer all comes analog representation with the chroma-luminance GTG on 0-255 rank with less section, and the brightness of formed color signal and the required acceleration driving voltage analogue value also are less than 65536 kinds far away.

Though these quicken the demand that the driving voltage analogue value has reduced storer,, for making it quickly and accurately near the actual driving voltage value that quickens, each tame dealer all comes the computing simulation with different specific functions, or polynomial function, or bilinear function, again or orthogonal function.Just these modes all are limited to the above-mentioned acceleration driving voltage analogue value and are with inference, suppose that mode obtains, therefore on the actual acceleration of simulation driving voltage value, often can't accurately reach, not only influence the reaction time of LCD screen, more influence its chroma-luminance effect.

The inventor of this case contributes to the display high-tech industry for a long time, the experience that accumulation is researched and developed in this field for many years, proposition can be reacted the signal processing method of chroma-luminance GTG quickly and accurately by functional operation OD value, handle upward preferable enhancement gray scale response speed effect to reach signal.

Summary of the invention

Fundamental purpose of the present invention provides a kind of signal processing method, quicken to drive OD voltage measured value by measuring, make OD measuring value table, obtain corresponding four OD compressed value tables with compress mode by above-mentioned OD measuring value table again, and obtain the OD reducing value by the functional operation mode, and handle to carry out the intensity gray scale response speed, to save great amount of hardware resources, effectively accelerate the intensity gray scale response speed and accurately show the actual color intensity gray scale.

For reaching above-mentioned purpose, the step of signal processing method of the present invention comprises:

1, measure the best OD magnitude of voltage of all GTG brightness correspondences in advance:

According to liquid crystal characteristic, in the mode that reality measures, find out desire to present the best OD magnitude of voltage of GTG brightness.This best OD magnitude of voltage is relevant with GTG value and present frame GTG value to be presented that former frame is presented, the man-to-man corresponding relation of tool, so this measurement can set up the OD measuring value table of one n * n, wherein n is grey exponent number.

2, set up funtcional relationship between OD value and the GTG value:

Simulate the relation of OD value and former frame GTG value and present frame GTG value with mathematical function.If represent former frame GTG value with x, represent present frame GTG value with y, then OD value z can be expressed as the function of x and y, that is z=f (x, y)=C * g (x) * h (y), wherein this mathematical function relationship can be polynomial expression (polynomial), bilinear relation (bilinear), the mathematical function of linear combination of orthogonal function (linearcombination of orthogonal functions) or arbitrary form.

3, the compression OD measuring value table and with its save as the table of comparisons (look-up table, LUT):

Extract the OD measuring value table of n * n, and with its boil down to m * m table of comparisons, m＜n wherein is so can effectively save storage space.

4, utilize the mathematical function of having set up that the table of comparisons is reduced to best OD reducing value:

Utilize the mathematical function of having set up, adopt bow and beam bearings, ask for best OD reducing value in curve convergence (curve fitting) mode, and with this OD reducing value driving display.

Compress the OD measuring value and draw the mode of OD reducing value by above-mentioned steps, and carry out the intensity gray scale response speed processing of screen panel with functional operation.

By last, a kind of signal processing method provided by the present invention not only can be saved hardware resource when implementing, and also can quicken the response speed of intensity gray scale and accurately show the chroma-luminance GTG.

Description of drawings

Figure 1 shows that the block diagram of one embodiment of the invention.

Figure 2 shows that the OD measuring value table of one embodiment of the invention.

Figure 3 shows that the OD table of comparisons of one embodiment of the invention.

Fig. 4 A-D is depicted as OD compressed value table P, Q, R and the S of one embodiment of the invention.

The figure number explanation

The 10 OD measuring value table 20 OD tables of comparisons

31 OD compressed value table P, 32 OD compressed value table Q

33 OD compressed value table R, 34 OD compressed value table S

Embodiment

The invention relates to a kind of signal processing method, especially refer to a kind of by measuring acceleration driving (overdriving) voltage measured value (being called for short the OD measuring value), and make OD measuring value table, obtain corresponding four OD compressed value tables with compress mode by above-mentioned OD measuring value table again, and obtain the OD reducing value to carry out the signal processing method of gray scale response velocity process by the functional operation mode, be applicable to liquid crystal panel (LCDPanel), plasma television (PDP), thin film transistor (TFT) (TFT) display or OLED, PLED organic electro-luminescent display isochrome colour display screen showing device.

See also shown in Fig. 1 to Fig. 4 D, present embodiment is to handle at the signal of the gray scale response speed on the LCD screen, and this redness GTG is an example with 5 signal, that is has 2 ⁵=32 intensity gray scale value outputs.

1, measure the best OD magnitude of voltage of all red GTG brightness correspondences of LCD screen in advance:

According to liquid crystal characteristic, mode with the reality measurement, find out desire to present the best OD magnitude of voltage of GTG brightness, this the best OD magnitude of voltage is relevant with GTG value and present frame GTG value to be presented that former frame is presented, the man-to-man corresponding relation of tool, therefore this measurement can be set up the array N of one n * n, and wherein n=32 is total GTG number; This array N also is called OD measuring value table 10.For example, when former frame GTG value is 16, present frame GTG value is 26, and then its corresponding OD measuring value is N _16,26

2, set up funtcional relationship between OD value and the GTG value:

This step is to simulate the relation of OD value and former frame GTG value and present frame GTG value with mathematical function.If represent present frame GTG value with x, represent former frame GTG value with y, then can set up N according to the OD measuring value _YxAnd the funtcional relationship f between x, the y (x, y).For example, when former frame GTG value is 16, according to measuring value N _16,1, N _16,2..., N _16,32Can simulate f (x, 16)=b * h ₁₆(x); Or when present frame GTG value is 26, then according to measuring value N _1,26, N _2,26..., N _32,26Can simulate f (26, y)=a * g ₂₆(y).Therefore,, can construction go out all OD value and x by numerical simulation, the funtcional relationship between the y, that is

N _yx＝f(x，y)＝C×h _y(x)×g _x(y)

Wherein C is normaliztion constant (normalization constant), and h _y(x) and g _x(y) then be mathematical function, its form can be polynomial expression (polynomial), bilinear relation (bilinear), the mathematical function of linear combination of orthogonal function (linear combination of orthogonal functions) or arbitrary form.

3, the compression OD measuring value table 10 and with its save as the table of comparisons 20 (look-up table, LUT):

Extract OD measuring value table 10, and with its boil down to table of comparisons 20; The array N that also is about to n * n extracts the array M of boil down to m * m, wherein m＜n.With 5 GTGs is example, can be with the OD table of comparisons 20 of 32 * 32 OD measuring value table 10 boil down to 8 * 8.The mode of this extraction compression can be utilized equidistant extraction method, and for example in array N, element of per 4 element extraction becomes array M, that is M _Ij=N _8i-7,8j-7, i wherein, j=1,2 ... m, the correspondence position of representing matrix element in matrix.In practical application, the mode of extracting compression is not limited to equidistant extraction method, if the OD value rate of change that some GTG value scope is found in actual measurement is bigger, can use the non-equidistance extraction method, as long as the relative position of this extraction of storage.

4, utilize the mathematical function of having set up that the OD table of comparisons 20 is reduced to best OD reducing value:

This step is to utilize the mathematical function of having set up, adopts bow and beam bearings, asks for best OD reducing value in curve convergence (curvefitting) mode, and with this OD reducing value driving display.Bow and beam bearings of the present invention is that the OD table of comparisons 20 further is divided into four compressed value table 31-34, is respectively P 31, Q 32, R 33 and S 34.Wherein the element corresponding relation of 20 li of the element in four compressed value tables and the OD tables of comparisons can be expressed as

P _kl＝M _2k-1，2l-1

Q _kl＝M _2k，2l-1

R _kl＝M _2k-1，2l

S _kl＝M _2k，2l，

K wherein, l=1,2 ... m/2, expression element corresponding position in matrix.That is to say that in the OD table of comparisons 20, four adjacent elements can usually represent with the corresponding unit of P 31, Q 32, R 33 and S 34, promptly

$\left[\begin{array}{cc}{M}_{i,j}& M_{i,j+1}\\ M_{i+1,j}& M_{i+1,j+1}\end{array}\right]\&equiv;\left[\begin{array}{cc}{P}_{\mathrm{kl}}& R_{\mathrm{kl}}\\ Q_{\mathrm{kl}}& S_{\mathrm{kl}}\end{array}\right]$

I wherein, j is the integer of odd number, and k=(i+1)/2, l=(j+1)/2.So P _KlWith Q _KlBetween and R _KlWith S _KlBetween have g respectively _j(y) and g _J+1(y) funtcional relationship, and p _KlWith R _KlBetween and Q _KlWith S _KlBetween then have h respectively _i(x) and h _I+1(x) funtcional relationship.

When the intensity gray scale of LCD screen in the former frame time is y, and when the intensity gray scale of present frame desire performance is x,, find out and (x, y) adjacent P by four compressed value table 31-34 _Kl, Q _Kl, R _KlAnd S _Kl, and according to pairing funtcional relationship g _j(y), g _J+1(y), h _i(x) and h _I+1(x), with curve convergence (curve fitting) mode or weighting in curve convergence (weighted curve fitting) mode, obtain best OD reducing value, and drive LCD screen with this OD reducing value and make LCD screen accurately show the brightness being desired to reach.

Below only can implement one of aspect, when can not be in order to limit scope of the present invention in order to disclose the present invention.All practise in the personage of this industry variation and the application implementation that obviously can do, all should be considered as not departing from flesh and blood of the present invention.

To sum up, the present invention has following advantage:

1, saves hardware resource: general known in order to process the signal processing method of intensity gray scale response speed Be to calculate and carry out with functional simulation, and the present invention is the actual OD measuring value that measures earlier the color displays device, Dwindle form with compress mode again and obtain the OD compressed value, and store the OD compressed value in storage assembly. By Come littlely in the required storage area of OD compressed value table far beyond OD measuring value table, therefore can save lower big The amount hardware resource.

2, accelerate the response speed of intensity gray scale: use the OD technology, obtain specific in the functional operation mode The OD magnitude of voltage, and carry out according to this intensity gray scale response of color displays device, can effectively accelerate the brightness ash The rank response speed.

3, accurately show the chroma-luminance GTG: the present invention is that the actual OD that measures earlier the color displays device measures Value obtains corresponding OD compressed value and function again, uses can reduce computing and obtain OD reduction Value, therefore, the present invention can accurately show the actual color intensity gray scale.

In sum, the content according to above disclosing for reaching expection purpose of the present invention, provides a kind of Obtain the OD reducing value with functional operation OD measuring value, and can carry out quickly and accurately the intensity gray scale response The signal processing method of velocity process applicable to all kinds of color displays devices, therefore proposes invention specially in accordance with the law Sharp application.

Claims (5)

1, a kind of signal processing method is that the intensity gray scale response speed that is used for screen panel is handled, and it is characterized in that its step comprises:

(1) measures the best OD magnitude of voltage of all GTG brightness correspondences in advance, according to liquid crystal characteristic, mode with the reality measurement, find out desire to present the best OD magnitude of voltage of GTG brightness, this the best OD magnitude of voltage is relevant with GTG value and present frame GTG value to be presented that former frame is presented, the man-to-man corresponding relation of tool, and set up the OD measuring value table of one n * n thus, wherein n is grey exponent number;

(2) set up funtcional relationship between OD value and the GTG value: the relation of simulating OD value and former frame GTG value and present frame GTG value with mathematical function;

(3) the OD measuring value table of extraction n * n, and with its boil down to m * m table of comparisons, wherein m＜n; And

(4) utilize the mathematical function of having set up that the table of comparisons is reduced to best OD reducing value, and with this OD reducing value driving display;

(5) compress the OD measuring value by above-mentioned steps and handle with the intensity gray scale response speed that the mode that functional operation draws the OD reducing value is carried out screen panel.

2, as the described signal processing method of above-mentioned claim 1, it is characterized in that: this funtcional relationship is the linear combination of polynomial expression, bilinear relation or orthogonal function.

3, as the described signal processing method of above-mentioned claim 1, it is characterized in that: this reduction is to utilize the mathematical function of having set up, adopts bow and beam bearings, asks for best OD reducing value in curve convergence mode.

4, as the described signal processing method of above-mentioned claim 1, it is characterized in that: this specific signal is meant the color signal.

5, as the described signal processing method of above-mentioned claim 1, it is characterized in that: this method is to be used for liquid crystal panel, plasma television, TFT thin film transistor monitor or OLED, PLED organic electro-luminescent display.

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